android - 如何在测试期间调用 oncreate 之前获取 Activity 引用

Question

如何在调用 onCreate 之前获取 Activity 的引用。虽然它正在接受测试。我使用 ActivityTestRule 作为 JUnit 规则。这个要求的原因是我想从测试中注入(inject)模拟到 Activity 中。

public class MyActivity extends Activity{

    MyComponent myComponent;

    @Override
    public void onCreate(Bundle savedInstanceState){
        super.onCreate(savedInstanceState);
        if(myComponent==null){
            myComponent ... //initialise dagger component
        }
        myComponent.inject(this);
        ...
    }

    public void setComponent(MyComponent comp){
        this.myComponent = comp;
    }
}

public class MyTest{

    @Rule
    public ActivityTestRule<MyActivity> intentsTestRule = new ActivityTestRule<>(MyActivity.class);


    MyComponent myFakeComponent;

    @Before                                      
    public void setUp() {                        
        MyActivity activity = intentsTestRule.getActivity();  
        activity.setComponent(myFakeComponent);
    }                                            

    @Test
    public void testMethod1(){...}
} 

Answer 1

根据文档，您在这里所做的是错误的。

@Rule
public ActivityTestRule<MyActivity> intentsTestRule = new ActivityTestRule<>(MyActivity.class);

MyComponent myFakeComponent;

@Before                                      
public void setUp() {                        
    MyActivity activity = intentsTestRule.getActivity();  
    activity.setComponent(myFakeComponent);
}              

因为，

This rule provides functional testing of a single activity. The activity under test will be launched before each test annotated with Test and before methods annotated with @Before. It will be terminated after the test is completed and methods annotated with After are finished. During the duration of the test you will be able to manipulate your Activity directly.

但是!

protected void beforeActivityLaunched ()

Override this method to execute any code that should run before your Activity is created and launched. This method is called before each test method, including any method annotated with @Before.

因此，如果您将 MainActivityComponent 的初始化移动到 Activity 之外的一个可模拟的位置，那么您将能够在创建主 Activity 之前将其组合在一起。

编辑:

另一种可能的解决方案是根据 link 延迟启动 Activity .

@Rule
public ActivityTestRule<NoteDetailActivity> mNoteDetailActivityTestRule =
        new ActivityTestRule<>(NoteDetailActivity.class, true /* Initial touch mode  */,
                false /* Lazily launch activity */);

@Before
public void intentWithStubbedNoteId() {
   // Add a note stub to the fake service api layer.
   FakeNotesServiceApiImpl.addNotes(NOTE);

   // Lazily start the Activity from the ActivityTestRule this time to inject the start Intent
   Intent startIntent = new Intent();
   startIntent.putExtra(NoteDetailActivity.EXTRA_NOTE_ID, NOTE.getId());
   mNoteDetailActivityTestRule.launchActivity(startIntent);

   registerIdlingResource();
}